1. Field of Invention
The present invention relates a pen-based computing device and in particular to the use of a partial ink layer.
2. Description of Related Art
A pen-based device, such as a PDA (personal data assistant) or a tablet-based computer, uses an LCD display overlaid by a transparent touch screen. Other devices, such as smart phones or other intelligent devices, are becoming available and may use small displays and pen-based input. The touch screen is used to input the location of a pen, or stylus, when the pen touches the surface of the touch screen. When the pen comes in contact with the touch screen, the CPU contained within the PDA interprets the X and Y coordinates of the location of the pen and performs operations depending on where the pen is located. A PDA like device uses several methods of data input, clicking on “soft” buttons or icons on the display screen, handwriting recognition, and text input using the pen on the touch screen. Handwriting can be character based by entering one character at a time or fully cursive where full words or phrases are entered at one time.
In U.S. Pat. No. 6,335,725 B1 (Koh et al.) a method is directed to partitioning a touch screen data input device into a main portion and a secondary portion. The first portion is accessible to a user using a stylus or pen and the second portion is accessible by a finger of the user holding the device. U.S. Pat. No. 6,160,555 (Kang et al.) is directed to a method to provide a cue for a user of a hand held device when entering or editing characters. U.S. Pat. No. 5,521,986 (Curtin II et al,) is directed to using a mosaic display as a template for imputing characters. The displayed mosaic has a plurality of segments, each represented by a tile area of the template.
In a pen based character input to a computing device, input is generally constrained to a area surrounding or near the initial pen-down point on the touch screen overlaying the display of the computing device. Input is generally by character, such as pen-down+pen stroke+pen-up. This is the case for Graffiti™ used on Palm OS devices with the exception of the multi-stroke characters. There are other forms of input that do not follow the simple character input steps like fully cursive input and Kanji characters, and in these multi-stoke cases it can also be found that once the initial pen point is known, the required entry will be located near or around the initial point of contact of the touch screen by the pen. The pen point alone does not provide enough information about the dimensions and orientation of the user entry; however, by monitoring the direction after the initial point of contact, it is possible to predict the confining area of entry by the user. Whereas, pen strokes of individual characters may traverse any direction while creating a character, the basic direction of character and word entry is unidirectional, such as left to right.